Polysulfones



3,290,272 POLYSULFONES Floyd L. Ramp, West Richfield, and Louis E. Trapasso, Maple Heights, Ohio, assignors to The B. F. Goodrich ,/United States Patent 3,290,272 Patented Dec. 6, 1966 "ice polymer obtained in aqueous sodium hydroxide at 60 C. for 3 hours. Alkali sensitivity is indicated by discoloration of the sample and extreme alkali sensitivity is shown if the sample dissolves.

Company New York, N'Yq a corporation of New York 5 T and T dynamic extrusion values were measured in No Drawing. Filed Dec. 7, 1962, Ser. No. 242,926 a dynamic extruslon rheometer. In the operat on of this 4 Claims. (CL 7 instrument a granular polymer sample 1s placed 1n a chamber under a plunger comprising a load of 3263 lbs./in. This invention relates to a unique resinous polysulfone The sample is gradually heated to effect its ultimate exand mom Particularly relates to a polysulfone P p 10 trusion through an orifice 0.0625 inch in diameter. m W P (nofbolnadiene) and Plunger advance and temperature increase are periodically sulfur dioxide. measured. Their plot provides a curve whose interpreta- It is known that polymeric sulfones with good t ermal tion enables the calculation of T and T values where T stability and fiber-forming properties may be obtained by is related to the second order transition temperature and oxidizing polymeric sulfides t0 th rresp n ing p y- T is related to the softening point of the polymer. meric sulfones if the oxidation of said sulfides is effected Thermal stability of the samples is evaluated in a pelby employing a peroxide compound, su as hy rogen let press consisting of a cylindrical die that can be heated peroxide of 30% to 90% strength as the oxidizing agent and cooled while held in the press at pressures up to in a solvent medium comprising concentrated formic 10,000 psi. The die is preheated to a selected temperacid. A simpler, more economic route to the polymeric ature and 2.0 grams of powdered polymer is added. About sulfones would be desirable. 5,000 p.s.i. pressure is applied to the sample and then re- Polysulfones obtained by copolymerization of sulfur leased. This step is repeated three times to remove any dioxide (a very low'cost monomer) with olefins are genvoids in the sample. Pressure of 10,000 p.s.i. is applied erally alternating copolymers containing a gamma disuland held for 2 minutes and then the die is cooled for fone repeating unit. Copolymers of sulfur dioxide with 20-30 minutes. The pressure is released and the pellet conjugated dienes are found to be vinylogs of polymeric removed for observation. Dark pellets indicate lack of gamma disulfones. These polymeric disulfones have the thermal stability. If no pellet has formed, the test is reundesirable properties of being thermally unstable and peated at a higher temperature. The. temperature at alkali sensitive. Polysulfones containing more than 2 which a light colored or colorless pellet forms is taken as saturated carbon atoms between the sulfone groups have, the top of the thermally stable range of the material. however, been shown to be quite stable toward heat and Infrared analysis of these copolymers show a peak at alkali (United States Patent 2,534,366). about 13.9 microns which is indicative of 1,2 addition and It has been speculated that a form of cyclocopolymerithe presence of unreacted double bonds in the polymer. zation might be effected wherein non-conjugated 1,5,1,6 If this peak is small, it is evidence that the predominant and higher dienes might be copolymerized with sulfur addition has been 1,5 in nature, that the double bonds dioxide and hence produce a chain of more'than 2 satare virtually all reacted, and that the polymer can be exurated carbon atoms between the sulfone groups. Experipected to be thermally stable and alkali insensitive. ments with bimethallyl, diallyl ether and 4-vinyl-1-cyclo- The main part of our invention having been described, hexene indicate, however, that the non-conjugated double the following examples are presented for its further debonds evidently react independently and the resulting ma- 40 scription and illustration: terials are again cross-linked and alkali sensitive.

We have surprisingly found that a thermally initiated Examples L1H copolymerization of sulfur dioxide and norbornadiene Distilled bicycloheptadiene mol) was charged into occurs predominantly by 1,5 homo-conjugative addition a polymerization tube flushed with nitrogen. Cold, disand forms a thermally stable, alkali resistant polysulfone. tilled S0 mol, B.P.10 C.) was added and the tube Our discovery is even more surprising in view of the fact was again flushed with nitrogen and sealed. Ethanolic that low temperature, free radical initiated copolymerizasilver nitrate (0.08 g. in 2% solution) was next charged tion of sulfur dioxide and norbornadiene produces mainly to the tube by means of a hypodermic syringe and polyma 1,2 addition repeating unit resulting in an alkali senerization was conducted at 4 C. The polymer formed sitive, thermally unstable polysulfone. was filtered, w-ater washed to remove silver nitrate and The polymerization of sulfur dioxide and norbornadried overnight in a vacuum oven at 100 C. The prodiene can be conducted by direct contact, as by bubbling cedure was run several times, producing the data sumthe gaseous dioxide through the liquid diene. For ease marized in the table below:

TABLE 1 Example Diene, S02, AgNO Solvent Temp., Time, C mment mols mols mols 0. hours I 3/32 4/32 1/2000 None 4 96 Button pressed at 260 0., very dark, very brittle extremely alkali sensitive. II 3/32 4/32 1/200() n-Hexane 4 48 Fused at 200 0., very dark, very brittle,

extremely alkali sensitive. III 3/32 4/32 1/2000 Tetrahydroturan 4 48 Dissolves in dilute alkali.

of handling, however, it is preferable to mix the diene Examples IV-VIII with an amount of a liquid organic medium such as A 300 ml. stainless steel autoclave was purged with ane, dimethyl sulfolane, dioxane and the like. nitrogen. Bicyclo [2,2,l]-2,5-hepta'diene was added to In the examples given below alkali resistance is determined by heating a 0.1-0.3 gram sample of the white 200 ml. of solvent in the autoclave. Sulfur dioxide was added by distillation from gas cylinder and the autothe majority of inorganic solvents. The only successful solvents found for these materials are concentrated sulfuric acid and phosphoric acid.

We claim:

1. The process of iorming an alkali insensitive sulfone polymer by thermal initiation at LOO -200 C. of polym-- erization between about 1 mol of monomeric bicyclo TABLE 2 Example Diene, S02, Solvent Temp, Time, Comment mols mols 0. hours IV 3/32 12/32 n-Hexane 150 3 T1=257 C., T =3Ol C. Alkali insensitive. V 3/32 9/32 do 150 18 T1=257 0., T2=302 O. Alkali insensitive.

LR. peak at 13.9s1nall. VI 3/32 9/32 d 150 3 T1=249 0., T =301 C. Alkali insensitive. LR. peak at 13.9-small. VII 3/23 9/32 Di0xane 200 3 T1=79 0., T2=119 C. Alkali insensitive.

LR. peak at 13.9small. VIII 3/32 1/32 n-Hexane 150 3 Fuses at 160 C. Alkali insensitive. LR.

peak at 13.9-small.

T-he copolymer of Example IV was submitted for micro analysis of carbon, hydrogen and sulfur and the results compared to theoretical analyses clearly indicate that the eopolymer of this invention is essentially in the 1:1 alternating lf'O'IlIl']. indicative of 1,5 addition rather than in the 2:1 dorm indicative of 1,2 addition.

Example V indicates that long heating has no effect on the copolymer formed. It is very heat stable. Examples VII and VIII indicate that varying the solvent {from hexane, and lowering the proportion of S0 charged do detract from thermal stability, but no particularly from alkali insensitivity of the polymers. Example VII further shows that polymerization temperatures up to 200 C. do not detract from the alkali insensitivity.

These new thenmally initiated copolymers can be plasticized with monomeric sulfones and molded into buttons or other desirable and useful shapes. They are extremely useful for forming plastic molded parts that will be exposed to heat, alkalinity, hydrocarbon solvents and References Cited by the Examiner UNITED STATES PATENTS 2,258,702 10/1941 Frey 260--79.3 2,930,781 3/1960 Schmerling 2'608 8.2 2,930,782 3/ 1960 Schmerling 260-882 3,133,903 5/1964 Frazer 260-8 8.2

OTHER REFERENCES Frederick et al.: Journal American Chemical Society,

vol. 56, pp. 18151819 1954 JOSEPH L. SCHOFER, Primary Examiner.

JAMES A. SEIDLECK, Examiner.

D. K. DENENBERG, J. F. McNALLY,

Assistant Examiners. 

1. THE PROCESS OF FORMING AN ALKALI INSENSITIVE SULFONE POLYMER BY THERMAL INITATION AT 100*-200*C. OF POLYMERIZATION BETWEEN ABOUT 1 MOL OF MONOMERIC BICYCLO 2,2,1!-2,5-HEPTADIENE AND ABOUT 1-4 MOLS OF MONOMERIC SULFUR DIOXIDE, SAID POLYMERIZATION BEING CONTINUED FOR A PERIOD OF 3-18 HOURS. 